Overmodulation.. Crackling.. -Sound Forge - PC - MAGIX Community Forums Archive

Subject:Overmodulation.. Crackling.. Posted by: fongaboo Date:2/19/2002 2:23:09 PM I know this is one of those cases of you-can't-squeeze-blood-from-a-stone.. or rather, can't erase a misspelling engraved in granite.. but.. Any suggestions for treating a recording that was recorded hot.. and is overmodulating to the extent that there is a lot of crackling? I'm wondering if a pop-removal algorithm for vinyl would help somewhat? I am not expecting to restore the audio to anywhere near the original.. just so it is not painful to listen to.. Approach my question with this mindset: imagine i am doing a documentary on a convenience store robbery, and trying to do something with bad audio from closed-circuit security footage.. and just want to show what happened without my audience wincing.. Thanks..
Subject:RE: Overmodulation.. Crackling.. Reply by: Chienworks Date:2/19/2002 6:44:42 PM It's a tad expensive, but the Noise Reduction plugin from Sonic Foundry has a "clipped peak restoration" function. This will round out those lost peaks and make them sound quite good. Once you've got the thing, i'm sure you'd find plenty of other uses for it too. One thing i've done dirt cheap when it's just a voice recording is to compress or reduce volume so that there are no peaks over about -3dB, then EQ to just the voice band (take out everything below 160Hz and above 3KHz), which causes the wave form to be recalculated and rounds off lots of the clipped peaks, and then apply a little bit of reverb to the whole file to give it a little warmth back and fill in some of the highs that the EQing lost, which also helps round out the clips a little more. This doesn't work at all well for music though.

Subject:Overmodulation.. Crackling..

Posted by: fongaboo

Date:2/19/2002 2:23:09 PM

I know this is one of those cases of you-can't-squeeze-blood-from-a-stone.. or rather, can't erase a misspelling engraved in granite.. but..

Any suggestions for treating a recording that was recorded hot.. and is overmodulating to the extent that there is a lot of crackling? I'm wondering if a pop-removal algorithm for vinyl would help somewhat?

I am not expecting to restore the audio to anywhere near the original.. just so it is *not* painful to listen to.. Approach my question with this mindset: imagine i am doing a documentary on a convenience store robbery, and trying to do something with bad audio from closed-circuit security footage.. and just want to show what happened without my audience wincing..

Thanks..

Subject:RE: Overmodulation.. Crackling..

Reply by: Chienworks

Date:2/19/2002 6:44:42 PM

It's a tad expensive, but the Noise Reduction plugin from Sonic Foundry has a "clipped peak restoration" function. This will round out those lost peaks and make them sound quite good. Once you've got the thing, i'm sure you'd find plenty of other uses for it too.

One thing i've done dirt cheap when it's just a voice recording is to compress or reduce volume so that there are no peaks over about -3dB, then EQ to just the voice band (take out everything below 160Hz and above 3KHz), which causes the wave form to be recalculated and rounds off lots of the clipped peaks, and then apply a little bit of reverb to the whole file to give it a little warmth back and fill in some of the highs that the EQing lost, which also helps round out the clips a little more. This doesn't work at all well for music though.